The present invention relates to a steel manufacturing system, particularly a min-steel plant, of the type in which steel is melted from iron carriers, preferably scrap or a similar starting material, and is continuously cast in a casting hall, with individual intermediate treatment stations being arranged in series and in a line with respect to the flow of material and the center of the station.
To save investment and production costs, the iron and steel industry has long attempted to reduce the investment required for their systems. The investment can be reduced, in particular, by shortening transportation paths. This applies for large systems, such as the so-called mini-steel plants which serve, in particular, for the production of steel from scrap. Generally, the scrap is melted into steel in an electric furnace, with or without preheating, and is cast continuously in an associated continuous caster. Although most of the prior art mini-steel plants have been erected as new structures, because they follow the known "classical" smelting plants too closely they are still too large and too expensive in design.
DE-OS (German published unexamined application) 3,316,367 discloses a method and apparatus for producing steel by means of oxygen bubbles. In this reference the melt is treated in a straight line from the furnace to the caster in metallurgical vessels which are moved on cars, with the straight line being in a hall. Alternatively, the use of 100% scrap is also contemplated without a separate melting furnace being employed. However, scrap cannot be melted economically in movable, oxygen heated ladles. The known problems of melting scrap without the addition of pig iron is thus not considered. Moreover, nothing is disclosed about the necessary process steps and system components, such as ladle return and preparation (lining), feeding in the required materials, and supply devices, to name but a few. The implementation of the proposed process for a specific system is thus questionable.